An instance of the Etherpad collaborative online editor is available at etherpad.h-da.de (nowadays provided by central IT). Etherpad allows multiple users to edit the same document with changes being synchronized in real time.
Upon accessing etherpad.h-da.de, you're greeted by the following prompt:
New Pad creates a new pad using a randomly-generated name and opens it in your browser. The resulting URL (which includes the pad name) can be sent to other users to allow them to join you in the live-editing process.
While it is possible to pick a name yourself (by entering it into the input
text field), be aware that the pad name also serves as an access token. Hence,
it is not advisable to choose a predictable name unless you want the pad to be
editable by everyone who is able to guess it. You can always append a more
friendly name to a randomly-generated string (e.g.
to make it easier to disambiguate the URLs of different pads.